Lung specimens of participating transplant patients will be collected at INOVA Fairfax Hospital. Patients who participate in the apheresis portion of the study will be admitted to the NIH Clinical Center for 2 to 3 days. Apheresis is a procedure for collecting large quantities of specific blood components. For this study, plasma-the liquid part of the blood-will be collected. For the procedure, whole blood is collected through a needle in an arm vein, similar to donating blood. The blood is separated into its components by centrifugation (spinning), the plasma and white cells are extracted and collected in a bag, and the red cells are returned to the body, either through the same needle or through another needle in the other arm.